ParticlePosition doesn't use Previous values

UE - Rendering - Architecture - Niagara - Jan 9, 2024

FHLSLMaterialTranslator::ParticlePosition does not return Previous information when request which can result in bad motion vector calculation. ...

Motion blur artifacting in MetaHuman Crowd demo

UE - Rendering - Features - Sep 10, 2026

This issue was reported by a licensee and we also hit it during dev work on the crowds demo. It seems that this may be a general issue with motion vectors and teleporting actors as there are variou ...

Timer does not update in Vehicle Game

Docs - Samples - Oct 5, 2016

When trying to test Vehicle game, the counter did not increase as time elapsed. This prevents being able to test if the lap function is working. Tested in 4.13.2 CL 3145013 and it was working. Thi ...

Utility functions in UEdGraph_ReferenceViewer are no longer exposed

UE - Editor - Content Pipeline - Content Browser - Oct 29, 2018

A number of utility functions are provided in UEdGraph_ReferenceViewer for building menu extenders. This class was originally included in the engine as part of the ReferenceViewer module, but was re ...

Reimport Skeletal Mesh break Morph Targets if you have Active Reduction on base LOD

UE - Editor - Content Pipeline - Import and Export - Aug 27, 2019

Recent change to Material Expression code missing a case for "exp2" function in switch (cpp)

zComponent - Archive - Mar 4, 2024

The function "FMaterialDerivativeAutogen::GetFunc1ReturnType(...)" does not have a case for "EFunc1::Exp2". Also found in Release-5.4, CL: 331987674 ...

Sequencer UpdateTimeCursorPosition can set TimeCursorPosition beyond the end of the track when stopping

UE - Anim - Sequencer - Oct 11, 2016

After calling Stop() in UpdateTimeCursorPosition (LevelSequencePlayer.cpp:392), we continue on to set TimeCursorPosition to NewPosition. At this point, NewPosition is beyond the end of the track. A ...

Evaluate ClampedPow material function

UE - Graphics Features - Mar 16, 2017

ClampedPow seems to have been added as a way to tackle common compile warnings and edge cases (particularly NaNs), but the code shouldn't be calling both an abs() then a max(). This causes negative ...

Some developers reporting incorrect Preview in VR resolution for Steam VR

UE - Platform - XR - Aug 18, 2020

VR Preview Window is the wrong resolution, just showing the top left portion of the entire view. Somewhat similar symptoms to -[Link Removed]-, not exactly the same though.   This issue has not be ...